Dimmer for electric lamps.



I. C. & C. F. WILLIAMS.

DIMMER FOR ELECTRIC LAMPS.

APPucATloN r|LED1uuE|2,191s.

1 ,2 1 6,756. Patented Feb. 20, 1917.

I BY

TTORNEY UNITED STATES PATENT OFFICE.

IRA C. WILLIAMS AND CHARLES F. WILLIAMS, OF ALBANY, INDIANA; SAID IRA C. WILLIAMS ASSIGNOR T0 CAREY W. DERRICKSON, OF INDIANAPOLIS, INDIANA.

DIMMER FOR ELECTRIC LAMPS.

specification of Letters Patent.

Patented Feb. 20, 1917 Application filed June 12, 1916. Serial No. 103,248.

To (Z 'au/tom it may concern Be it known that we, IRA C. lViLLmMs and CHARLES F. W'ILLIAMS, citizens of the United States, and residents of Albany, county of Delaware, and State of Indiana, have invented a, certain new and useful Dimmer for Electric Lamps; and we do hereby declare that the following is a. full, clear, and exact description thereof, reference being had to the accompanying drawings, in which like letters refer to like parts.

This invention relates principally to a means for dimming electric lights, but may also be 'used as a rheostat for any other purpose.

The principal feature of the invention is to make as simple and compact as possible, a rheostat 01' resistance coil having therein a means for cutting in and out the resistance. To accomplish this result, a transverse section of the coil is raised above its surface, said raised Sections extending slightly oblique to the coil, and a means is provided on the housing thereof for engaging the raised Sections as the housing is turned, whereby the resistance will be cut in and out and varied with the turning of the housing.

The full nature of the invention will be understood from the accompanying drawings and the following description and claims.

Figure 1 is a Vertical cross section taken through the housing, and showing the coil in side elevation. Fig. 2, is a cross section on the line 2-2 of Fig. 1 showing the resistance cutout. Fig. 3 is a cross section on line 3-3 of Fig. 1 showing all the resistance cut in. Fig. 4 is the same as Fig. 3 showing the contact with the coil broken.V Fig. 5 is a cross section through the housing, showing the front elevation of the coil. Fig. 6 is the cross section of Fig. 1 on line 6--6 with the housing turned in the same position as in Fig. 2. Fig. 7 is the same as Fig. 6 showing the housing turned in the same position as in Fig. 4.

In the drawings there is shown a porcelain spool 10 about which a coil of fine wire 11 is wrapped, one end of said coil being connected to the eircuit 12, in which there is a lamp 13. The other end of the Wire coil is secured to the insulation at the top thereof. Running diagonally across the surface of the spool, there is a raised portion 14 extending from the bottom to the top over which the coil of wire passes. The wires are insulated from each other, but their surfaces are exposed for contact purposes over the raised portion of the spool.

Adapted to fit snugly over said spool, there is a housing 15 which has a stop screw 16 in its upper periphery adapted to engage the segmental recess 17 in said spool, so that said housing will be held in place by means of the stop screw 16 extending under the flange portion 18 formed by the recess 17, and will be limited in its movement thereby. On one side of said housing, a metal bar 19 is secured by means of the screws 20, which are insulated from the housing by the insulating covers 21. A segmental contact bar 22 is secured at one end to the lower screw 20, so as to make contact with the bar 19, and extends circumferentially between the lower part of the housing and spool, and is secured to the bar 19 and housing by the screws 20 and 23 which are insulated therefrom. The lower part of the spool has a recess 24 in which there is a coil spring 25 pressing against a contact brush 26, so that said brush is always in contact with the bar 22 as the housing is turned about its axis. Said brush being connected to the other end of-the circuit 12.

When the housing is turned about the vspool so that the bar 19 engages the raised Sections of the wire as shown in Figs. 1 and 52. the circuit 12 is closed through the lamp 13, the lower wires of the coil, the bars 19 and 22 and the brush 26. In this position as shown in Fig. 1 the resistance is cut out. When the said housing is turned as indicated by the arrow in Fig. 2, to the position shown in Fig. 3 the bar 19 engages the raised Sections of the wire only at the top of the coil so that the circuit then includes the resistance of the coil and the light is dim. By turning the housin to the left as indicated by the arrow in ig. 3 the resistance is gradually cut out and the light brightened. while by turning itin the opposite direction the resistance is cut in and the light is dimmed. It may therefore, be readily seen that the light may be dimmed to any degree desired by turning the housing slightly with the fingers, and this result is accomplished by means of a very simply constructed device, so that it may be made very small and placed in a convenient position to be operated.

The invention clailncd is:

1. A rheostat including a resistance Wire for-med in a coil, a spool, a ridge on the surface of said spool about which said coii passes7 a bar connected to said resistance Wire, a contact brush secured within said spool for making contact With said. bar, and means for engaging and making contact With the raised portion of said coii for Cutting in and out said resistance.

2. A rheostat including a resistance Wire :torxned in a coil7 of a spool, a ridge on the surface of said spool about which said c'oil passes, a housing adapted to inclose said Lamp/ae spool, a contact bar secured to said housing and adapted to make contact With said coii as it engages said ridge for Cutting in and out said resistance, a bar connected to said resistance Wire passing circulnferentially aroundl the lower portion of said housing, and a contact brush secured within said spool 'for making contact With said last mentioned baro In witness whereof, We have hereunto affixed our signatures.

IRA C. WILLAMS. CHARLES F. WLLIi-HVE.

Gopes of this patent may be obtained for five cents each, by adressing the 'Commssioner of Patents,

i Washington, 

